Lamp distributions

We will now look at an example of non-sequential ray tracing in ZEMAX.

Open the file "Samples > Non-sequential > Faceted objects > 3 helical lamps with reflectors.zmx". The file shows rays traced from three lamps onto three detectors. Zoom in on one of the lamps in the NSC 3D Layout window and you will then see the helical structure of the sources being modeled. In this example, each lamp is simulated using the Source Filament NSC object type which is a coiled helix. Rays are launched from random points along the helix and then reflect off of the faceted reflectors surrounding each helix.

NSC 3D Layout showing helical structure of sources

From the main menu bar, select the option, "Analysis > Detectors > Ray Trace/Detector Control". A dialog box will open. This dialog is used to trace analysis rays. Click the button "Clear Detectors", and the detectors will be cleared. Next click the "Trace" button. This will trace a new set of random analysis rays to the detectors. Click the "Exit" button once the ray trace is complete.

To view the results of the ray trace, open a Detector Viewer. This can be done via the main menu option, "Analysis > Detectors > Detector Viewer". The Detector Viewer will default to the first detector object in the list of objects in the Non-Sequential Editor which is object 10.

Detector Viewer showing output on detector object 10

Click on "Settings" from the Detector Viewer window menu bar. To change the detector viewed, change the "Detector" setting from "Detector Object 10" to another detector object and then click "OK".

TIP: To see where a detector is placed and determine its orientation, click anywhere on the row corresponding to the detector in the Non-Sequential Component Editor (NSCE). The rectangle corresponding to the detector will be highlighted in red in the NSC 3D Layout window. Here is the layout window shown when detector object 11 is selected.

NSC 3D Layout showing detector object 11 highlighted

In this example ten thousand analysis rays are traced from each source during each trace. The number of rays traced for detector analysis is set for each source in the Non-Sequential Component Editor. The number of rays can be changed in the full, licensed version of ZEMAX. To see where the number of rays is defined, click on a row corresponding to any of the Source Filament objects (objects 3, 6 and 9) in the Non-Sequential Component Editor. Next, move the cursor to the right with the right arrow key until you see a column with the title "# Analysis Rays" displayed. The NSC Editor has "active" column headings like the Lens Data Editor. The column headings change to tell you what the values are in each cell depending upon the type of object that you have selected.

Non-sequential Component Editor

The "# Layout Rays" in this example is set to 5 for each source object. The number of layout rays is set separately from the number of analysis rays so that layout windows do not become confusing when thousands upon thousands of rays are traced for analysis. Each time you double click on an open layout window, or select "Update" from a layout window's menu bar, a new set of random layout rays will be drawn.

NSC Shaded Model layout windows can show the results of analysis traces. This option is controlled via the "Detectors" option in the NSC Shaded Model window settings. If this setting is set to "Color pixels by last analysis", then detector objects in the layout will be drawn based on the results of the last analysis trace.